Plank Resting on Two Supports

Since we have two unknownsandassuming W is known, besides the equation above, we need one other equation to findandWe can obtain this equation by taking moments, either aboutorTaking moments aboutgivesand from this we obtain

Substituting this into (1) gives

Suppose now that someone stands on the plank. The weight of the person is twice the weight of the plank, and they stand betweenand1m from